|Meka Saima Perdani||1. Department of Chemical Engineering, Faculty of Engineering, Universitas Indonesia, Kampus UI Depok, Depok 16424, Indonesia 2. Department of Chemical, Faculty of Mathematic and Natural Sciences, I|
|Mohammad Didy Juliansyah||Department of Chemical Engineering, Faculty of Engineering, Universitas Indonesia, Kampus UI Depok, Depok 16424, Indonesia|
|Dwini Normayulisa Putri||Department of Chemical Engineering, Faculty of Engineering, Universitas Indonesia, Kampus UI Depok, Depok 16424, Indonesia|
|Tania Surya Utami||Department of Chemical Engineering, Faculty of Engineering, Universitas Indonesia, Kampus UI Depok, Depok 16424, Indonesia|
|Chairul Hudaya||Department of Electrical Engineering, Faculty of Engineering, Universitas Indonesia, Kampus UI Depok, Depok 16424, Indonesia|
|Masafumi Yohda||Department of Biotechnology and Life Science, Faculty of Engineering, Tokyo University of Agriculture and Technology, Tokyo 183-8538, Japan|
Cholesterol oxidase, a bio-catalyst that can catabolize cholesterol, has proven applications in medicine. Here, a support material was used to enhance the characteristics of the enzyme. Magnetite (Fe3O4) is widely used as an enzyme support; however, the interaction between the enzyme and the support should be capped with another material, such as chitosan biopolymer-based material. In this study, chitosan-magnetite materials were synthesized by mixing both compounds and activating with glutaraldehyde. The materials were then characterized by Fourier Transform Infrared (FTIR) Spectroscopy. The enzyme kinetic parameters were studied by following the cholesterol oxidation reaction using high-performance liquid chromatography (HPLC) and comparing the results between the free and the immobilized enzyme. The substrate concentration was 2.5 mg/mL. The effect of enzyme concentration was tested using different concentrations of enzyme (0.5, 1, and 2 mg/mL) to determine the best operating conditions. The best conditions for the oxidation reaction were immobilized enzyme at a 2 mg/mL concentration. Enzyme immobilization significantly decreased the optimum substrate concentration to 0.1 mg/mL.
Cholesterol; Cholesterol oxidase; Immobilized enzyme; Magnetite; Oxidation
Cardiovascular disease is related to heart and vein malfunctions and can include coronary heart disease, heart malfunction, hypertension, and stroke. According to the World Health Organization (WHO), cardiovascular disease causes 17.9 million deaths every year, or 31% of all annual deaths worldwide, making this the number one cause of global death. The most significant cause of cardiovascular disease is cholesterol, which accounts for 56% of cardiovascular disease (Mackay et al., 2004). Cholesterol is needed by the human body but is dangerous when present in excessive amounts. For this reason, blood cholesterol amounts should be monitored periodically. Cholesterol is monitored by two methods: chemical and enzymatic.
The enzymatic method is more advantageous, as it is not corrosive and is run as a specific reaction. However, the enzymatic method still has disadvantages that include enzyme inactivation under abnormal conditions of temperature and pH. The specific enzyme used for enzymatic cholesterol is cholesterol oxidase. This enzyme is produced by several pathogenic and non-pathogenic microorganisms, such as Mycobacterium, Brevibacterium, Streptomyces, Corynebacterium, Arthrobacter, Pseudomonas, Rhodococcus, Chromobacterium, and Bacillus species. Cholesterol oxidase from Streptomyces sp. can also reportedly oxidize the substrate from fatty foods and can degrade up to 80% of the initial concentration of the substrate (Perdani et al., 2019a).
Cholesterol oxidase kinetic behavior has been investigated with a first order irreversible reaction model. The enzymatic reaction needs one or two enzymes to break the structure into a complex component (Perdani et al., 2019b). The enzyme acts as an electron donor to the CH-OH group in cholesterol. The final cholesterol enzymatic oxidation product is 5-cholesten-3-one, which is isomerized through three stages to produce 4-cholesten-3-one (Devi and Kanwar, 2017). In the first catalytic stage, dehydrogenation of the OH group results in the loss of two hydrogen molecules in the third steroid ring. The released hydrogen molecules are transferred to the FAD enzyme cofactor so that FAD is reduced. The reduced FAD cofactor then reacts with oxygen molecules to restore the initial condition of the enzyme, where the FAD is re-oxidized and the hydrogen atom reacts to form H2O2. The final stage of this process is the isomerization of the double-chain steroid ring and production of the final product, 4-cholesten-3-one (Devi and Kanwar, 2017).
Enzymatic methods have been applied in many research applications, such as renewable energy, bio-products, and pharmaceuticals. Enzymes can have multiple functions and can be used as catalysts, extraction agents, and capping agents. The process parameters of temperature, enzyme substrate concentration, and extraction time have the greatest effects on the enzymatic reaction. In addition, the reaction slows down unless enzyme is continuously added (Handayani et al., 2018). However, a study of enzymes used as biocatalysts to produce biodiesel has shown that immobilization of the lipase enzyme by an adsorption-crosslinking method stabilized the enzyme and kept it soluble in the reaction. Assays of the immobilized enzyme in the biodiesel synthesis reaction revealed that it retained 84% of its initial activity (Aliyah et al., 2016). Similarly, Hermansyah et al. (2018), examined a lipase enzyme from Pseudomonas aeruginosa by a fermentation method for biodiesel production from palm oil mill effluent (Hermansyah et al., 2018). Therefore, immobilization is a commonly used method to improve enzyme activity.
Enzyme immobilization requires a material that will act as a support to stabilize the enzyme. Various kinds of supports are used for immobilization, including polymers, carbon, metals, or metal-metal combinations. One common support used in enzyme immobilization is chitosan. Chitosan is a biopolymer with a number of advantages; it is renewable, nontoxic, and highly available in Nature (Peter, 1995). In industrial applications, chitosan is a source for composites of activated clinoptilote zeolite/chitosan used as a support for biogas purification (Kusrini et al., 2019). According to Ahmad and Goswami (2014), chitosan also can be used as a support for bioreactions. It can improve the characteristics of the cholesterol oxidase enzyme against changes in reaction temperature. For example, the activity of an immobilized enzyme can be maintained up to 50°C, where it can still show 77% activity after 12 repeated enzyme reaction cycles (Ahmad and Goswami, 2014).
Chitosan and agarose are the most common biopolymers used as enzyme immobilization supports. Biopolymers used as immobilization supports bind the enzyme by adsorption and covalent bonding as immobilization techniques. However, the ability of biopolymers to form geometric structures, such as gel forms, makes them also useful for immobilization techniques involving encapsulation and entrapment (Zdarta et al., 2018).
In addition to biopolymers, inorganic and organic materials are also widely used in the preparation of enzymes, due to their specific characteristics. Magnetite particles have been attracting much interest for the development of many applications because of their unique properties, such as small size, superparamagnetism, low toxicity, good biocompatibility, and high surface area. Previous studies have also confirmed that bioenzymes can be immobilized with magnetic chitosan. The ability to undergo covalent binding produced strong enzyme activity and immobilization was confirmed by characterization of the sample with FTIR (Hamzah et al., 2019).
Magnetite nanoparticles dispersed in chitosan have been used as an electrochemical detector for the determination of the endocrine disruptor parathion. This composite showed good detection of the specific target compound. Chitosan has also been used to improve the stability of magnetite and to functionalize the surface of particles. The performance of a detector was improved with an electrode modified with magnetite and chitosan when compared with an unmodified electrode. The adsorption of magnetite was also increased after the addition of chitosan, as the matrix components of chitosan had a great influence on magnetite (Piovesan et al., 2018).
Magnetite-chitosan materials are widely used because of their easy separation and great support. A lipase enzyme covalently immobilized with magnetite chitosan was found to maintain 75.5% of its initial activity for 6 h. The magnetite chitosan has a great influence on the specific properties of enzyme, as it allows the creation of monolayers composed of different types of lipids, sterols, and their mixtures (Suo et al., 2018). In the present research, magnetite chitosan has been used as a support for cholesterol oxidase.
Magnetite chitosan has also been used for non-enzymatic reactions, but non-enzymatic reactions are slower than enzymatic methods. The aim of the present study was to explore the use of modified magnetite chitosan for the enzymatic reaction of cholesterol oxidation. A further aim was to investigate the effect of enzyme immobilization on the oxidation reaction between immobilized cholesterol oxidase and its substrate. The enzyme was tested for its ability to conduct the oxidation reaction by varying the enzyme concentration, substrate concentration, and reaction time. The immobilized enzyme material was characterized by Fourier transform infrared (FTIR) spectroscopy and the oxidation reaction was quantified by high performance liquid chromatography (HPLC).
Cholesterol oxidase immobilized with chitosan magnetite was able to oxidize up to 90% of a cholesterol substrate at different reaction times. The enzyme interacted with magnetite nanoparticles covered with aminated chitosan. The NH2 functional group was recorded during the immobilization step. Cholesterol oxidation with the immobilized enzyme showed that the use of a support material can significantly change the behavior of the enzyme to oxidize the substrate. However, the concentration of enzyme also affected the behavior of the oxidation reaction. Chitosan-magnetite could be a candidate for a cholesterol biosensor due to the sensitivity of the oxidation reaction for the substrate. The chemical properties are better for the immobilized enzyme than for the free enzyme. The best concentration of the immobilized enzyme for substrate oxidation was 2 mg/mL with the maximum reaction time.
Ahmad, S., Goswami, P., 2014. Application of Chitosan Beads Immobilized Rhodococcus sp. NCIM 2891 Cholesterol Oxidase for Cholestenone Production. Process Biochemistry, Volume 49(12), pp. 2149–2157
Aliyah, A. N., Edelweiss, E. D., Sahlan, M., Wijanarko, A., Hermansyah, H., 2016. Solid State Fermentation Using Agroindustrial Wastes to Produce Aspergillus Niger Lipase as a Biocatalyst Immobilized by an Adsorption-Crosslinking Method for Biodiesel Synthesis. International Journal of Technology, Volume 7(8), pp. 1393–1404
Bezdorozhev, O., Kolodiazhnyi, T., Vasylkiv, O., 2017. Precipitation, Synthesis and Magnetite Properties of Self-assembled Magnetite-Chitosan Nanostructures. Journal of Magnetism and Magnetic Materials, Volume 428, pp. 406–411
Devi, S., Kanwar, S.S., 2017. Cholesterol Oxidase: Source, Properties, and Application. Insight in Enzyme Research, Volume 1(1), pp. 1–5
Freire, T.M., Dutra, L.M.U., Queiroz, D.C., Ricardo, N.M.P.S., Barreto, K., 2016. Fast Ultrasound Assisted Synthesis of Chitosan-based Magnetite Nanocomposite as a Modified Electrode Sensor. Carbohydrate Polymers Journal, Volume 151, pp. 760–769
Ghosh, S., Ahmad, R., Khare, S.K., 2017. Immobilization of Cholesterol Oxidase: An Overview. The Open Biotechnology Journal, Volume 12, pp. 176–188
Hamzah, A., Ainiyah, S., Ramadhani, D., Parwita, G.E.K., Rahmawati, Y., Soeprijanto, Ogino, H., Widjaja, A., 2019. Cellulase and Xylanase Immobilized on Chitosan Magnetic Particles for Application in Coconut Husk Hydrolysis. International Journal of Technology, Volume 10(3), pp. 613–623
Handayani, D., Amalia, R., Yulianto, M.E., Hartati, I., Murni, M., 2018. Determination of Influential Factor during Enzymatic Extraction of Ginger Oil using Immobile Isolated Cow Rumen Enzymes. International Journal of Technology, Volume 9(3), pp. 455–463
Hermansyah, H., Maresya, A., Putri, D.N., Sahlan, M., 2018. Production of Dry Extract Lipase from Pseudomonas aeruginosa by the Submerged Fermentation Method in Palm Oil Mill Effluent. International Journal of Technology, Volume 9(2), pp. 325–334
Kusrini, E., Arbianti, R., Sofyan, N., Abdullah, M.A.A., Andriani, F., 2014. Modification of Chitosan by using Samarium for Potential Use in Drug Delivery System. Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 120, pp. 77–83
Kusrini, E., Shiong, N.S., Harahap, Y., Yulizar, Y., Arbianti, R., Pudjiastuti, A.R., 2015. Effects of Monocarboxylic Acids and Potassium Persulfate on Preparation of Chitosan Nanoparticles. International Journal of Technology, Volume 6(1), pp. 11–21
Kusrini, E., Wu, S., Susanto, B.H., Lukita, M., Gozan, M., Hans, M.D., Rahman, A., Degirmenci, V., Usman, A., 2019. Simultaneous Absorption and Adsorption Processes for Biogas Purification using Ca(OH)2 Solution and Activated Clinoptilolite Zeolite/Chitosan Composites. International Journal of Technology, Volume 10(6), pp. 1243–1250
Mackay, J.G., Mensah, S., Mendis, K., Greenland, 2004. The Atlas of Heart Disease and Stroke. World Health Organization, USA
Mohamad, N.R., 2015. An Overview of Technologies for Immobilization of Enzymes and Surface Analysis Technique for Immobilized Enzymes. Biotechnology & Biotechnological Equipment Journal, Volume 29, pp. 205–220
Perdani, M.S., Faturrohman, M., Putri, D.N., Hermansyah, H., 2019a. Oxidation of Cholesterol from Fatty Food by using Crude Cholesterol Oxidase Streptomyces sp. In: AIP Conference Proceedings, Volume 2193(1), pp. 1–6
Perdani, M.S., Sahlan, M., Farida, S., Putri, D.N., Soekanto, S.A., Hermansyah, H., 2019b. Kinetic Study of Cholesterol Oxidation by Cholesterol Oxidase Enzyme as Application for Cholesterol Biosensor. In: AIP Conference Proceedings, Volume 2092(1), 030027
Perdani, M.S., Sahlan, M., Yohda, M., Hermanysah, H., 2020. Immobilization of Cholesterol Oxidase from Streptomyces sp. on Magnetite Silicon Dioxide by Crosslinking Method for Cholesterol Oxidation. Applied Biochemistry and Biotechnology, Volume 191(8), pp. 968–980
Peter, M., 1995. Applications and Environmental Aspects of Chitin and Chitosan. Journal of Macromolecular Science, Volume 32(4), pp. 629–640
Piovesan, J.V., Haddad, V.F., Pereira, D.F., Spinelli, A., 2018. Magnetite Nanoparticles/Chitosan-modified Glassy Carbon Electrode for Non-enzymatic Detection of the Endocrine Disruptor Parathion by Cathodic Square-wave Voltammetry. Journal of Electroanalytical Chemistry, Volume 823, pp. 617–623
Ramachandran, R., Jung, D., Spokoyny, A.M., 2019. Cross-linking Dots on Metal Oxides. NPG Asia Materials, Volume 11(1), pp. 1–4
Suo, H., Xu, L., Xu, C., Chen, H., Yu, D., Gao, Z., Huang, H., Hu, Y., 2018. Enhancement of Catalytic Performance of Porcine Pancreatic Lipase Immobilized on Functional Ionic Liquid Modified Fe3O4-Chitosan Nanocomposites. International Journal of Biological Macromolecules, Volume 119, pp. 624–632
Tang, E.S., Huang, M., Lim, L.Y., 2003. Ultrasonication of Chitosan and Chitosan Nanoparticles. Journal of Pharmaceutics, Volume 265(1-2), pp. 103–114
Wang, X-Y, Jiang, X-P., Li, Y., Zeng, S., Zhang, Y-W., 2015. Preparation Fe3O4 @chitosan Magnetic Particles for Covalent Immobilization of Lipase from Thermomyces lanuginosus. International Journal of Biological Macromolecules, Volume 75, pp. 44–50
Xu, R., Zhou, Q., Li, F., Zhang, B., 2013. Laccase Immobilization on Chitosan/Poly (vinyl alcohol) Composite Nanofibrous Membranes for 2, 4-Dichlorophenol Removal. Chemical Engineering Journal, Volume 222, pp. 321–329
Zdarta, J., Meyer, A.S., Jenionowski, T., Pinelo, M., 2018. A General Overview of Support Materials for Enzyme Immobilization: Characteristics, Properties, Practical Utility. Catalysts, Volume 8(3), p. 1–27